RNAi-MEDIATED INHIBITION OF HIF1A FOR TREATMENT OF OCULAR ANGIOGENESIS

ABSTRACT

RNA interference is provided for inhibition of HIF1A mRNA expression for treating patients with ocular angiogenesis, particularly for treating retinal edema, diabetic retinopathy, sequela associated with retinal ischemia, posterior segment neovascularization (PSNV), and neovascular glaucoma, and for treating patients at risk of developing such conditions.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 17/224,327, filed Apr. 7, 2021 which is a continuation of U.S.patent application Ser. No. 17/115,743, filed Dec. 8, 2020 which is acontinuation of U.S. patent application Ser. No. 17/003,305, filed Aug.26, 2020 which is a continuation of U.S. patent application Ser. No.16/877,764, filed May 19, 2020 which is a continuation of U.S. patentapplication Ser. No. 16/784,402, filed Feb. 7, 2020 which is acontinuation of U.S. patent application Ser. No. 16/667,345, filed Oct.29, 2019 which is a continuation of U.S. patent application Ser. No.16/512,744, filed Jul. 16, 2019, which is a continuation of U.S. patentapplication Ser. No. 16/404,795, filed May 7, 2019, which is acontinuation of U.S. patent application Ser. No. 16/259,107, filed Jan.28, 2019, which is a continuation of U.S. patent application Ser. No.16/193,617, filed Nov. 16, 2018, which is a continuation of Ser. No.15/470,060, filed Mar. 27, 2017, which is a continuation of Ser. No.14/566,234, filed Dec. 10, 2014, which is a divisional of U.S. patentapplication Ser. No. 13/904,431 filed May 29, 2013 (now U.S. Pat. No.8,940,887), which is a divisional of U.S. patent application Ser. No.13/474,405 filed May 17, 2012, (now U.S. Pat. No. 8,471,000), which is adivisional of U.S. patent application Ser. No. 13/113,782 filed May 23,2011 (now abandoned), which is a divisional of U.S. patent Ser. No.12/706,014 filed Feb. 16, 2010 (now U.S. Pat. No. 7,981,870), whichclaims benefit to U.S. patent application Ser. No. 11/642,016 filed Dec.19, 2006 (now abandoned), which claims benefit to U.S. ProvisionalPatent Application Ser. No. 60/754,956 filed on Dec. 29, 2005, thedisclosure of each of which is specifically incorporated by referenceherein.

FIELD OF THE INVENTION

The present invention relates to the field of interfering RNAcompositions for inhibition of expression of hypoxia-inducible factor-1α(HIF-1α), the protein encoded by HIF1A mRNA, in ocular angiogenesis,including those cellular changes resulting from the transcription factoractivity of HIF-1α that lead directly or indirectly to ocularneovasularization, retinal edema, diabetic retinopathy, sequelaassociated with retinal ischemia, posterior segment neovascularization,and neovascular glaucoma, for example.

BACKGROUND OF THE INVENTION

Diabetic retinopathy (DR) is an eye disease that develops in diabetesdue to changes in the cells that line blood vessels, i.e. the retinalmicrovascular endothelium. During diabetes mellitus, hyperglycemia cancause damage in a number of ways. For example, glucose, or a metaboliteof glucose, binds to the amino groups of proteins, leading to tissuedamage. In addition, excess glucose enters the polyol pathway resultingin accumulations of sorbitol. Sorbitol cannot be metabolized by thecells of the retina and can contribute to high intracellular osmoticpressure, intracellular edema, impaired diffusion, tissue hypoxia,capillary cell damage, and capillary weakening. Diabetic retinopathyinvolves thickening of capillary basement membranes which may in turnprevent pericytes, the predominant perivascular cell type in retinalcapillaries, from contacting endothelial cells. Pericyte and endothelialcell death occurs through an apoptotic mechanism during diabeticretinopathy, where the loss of pericytes likely increases thepermeability of the capillaries and leads to breakdown of theblood-retina barrier and blood flow dysregulation. Weakened capillarieslead to aneurysm formation and further leakage. These effects ofhyperglycemia can also impair neuronal functions in the retina. DR isassociated with retinal microaneurysms, hemorrhages, exudates, andretinitis proliferans, i.e., massive neovascular and connective tissuegrowth on the inner surface of the retina. Diabetic retinopathy may beof the background type, progressively characterized by microaneurysms;intraretinal punctate hemorrhages; yellow, waxy exudates; cotton-woolpatches; and macular edema. This is an early stage of diabeticretinopathy termed nonproliferative diabetic retinopathy.

As the diabetes-induced microvascular pathology progress, retinalcapillaries eventually become occluded and lead to multifocal areas ofischemia hypoxia within the retina. Hypoxic conditions in thenon-perfused tissue causes an increase in HIF-1α levels. The resultingchanges in HIF-1-mediated gene expression elicits the production ofgrowth factors capable of stimulating abnormal new blood vessel growthfrom existing vessels (angiogenesis). These pathologic new blood vesselsgrow into the vitreous and can cause loss of sight, a condition calledproliferative diabetic retinopathy (PDR), since the new blood vesselsare fragile and tend to leak blood into the eye. The proliferative typeof DR is characterized by neovascularization of the retina and opticdisk which may project into the vitreous, proliferation of fibroustissue, vitreous hemorrhage, and retinal detachment.

Neovascularization also occurs in a type of glaucoma called neovascularglaucoma in which increased intraocular pressure is caused by growth ofconnective tissue and new blood vessels upon the trabecular meshwork.Neovascular glaucoma is a form of secondary glaucoma caused byneovascularization in the chamber angle.

Posterior segment neovascularization (PSNV) is a vision-threateningpathology responsible for the two most common causes of acquiredblindness in developed countries: exudative age-related maculardegeneration (AMD) and PDR. Until recently, the only approved treatmentsfor PSNV that occurs during exudative AMD were laser photocoagulation orphotodynamic therapy with VISUDYNE™. Both therapies involve occlusion ofaffected vasculature, which results in permanent, laser-induced damageto the retina, and does not address the underlying cause ofneovascularization. Recurrence of neovascularization from the same areais common. For patients with PDR, surgical interventions with vitrectomyand removal of preretinal membranes are the only options currentlyavailable, as well as a laser therapy called panretinal photocoagulationto prevent the production of more new vessels.

Current pharmaceutical efforts have focused on inhibiting the effects ofpotent angiogenic factors such as VEGF, a gene that is regulated byHIF-1. Recently, intravitreal injection of LUCENTIS™, an anti-VEGFantibody fragment, was approved for treatment of AMD. This antibodyfragment was designed to bind to and inhibit VEGF to inhibit theformation of new blood vessels. Lucentis is also in clinical trials forthe treatment of diabetic macular edema. Other approaches include theuse of small interfering RNA targeting VEGF or its receptor.

Disruption of the interaction between the HIF-1 transcription factor andthe hypoxia response element in oxygen sensitive promoters usingconventional small molecule inhibitors is likely to be very difficult.Like VEGF, HIF1A is not considered to be “druggable” in the classicalsense. Furthermore, the silencing of individual downstream effectors ofHIF-1, such as VEGF or RTP801, may only partially blockneovascularization.

The present invention addresses the above-cited problems and providesinterfering RNAs targeting HIF1A, the transcriptional control gene fordownstream genes involved in angiogenesis and vascular permeability(edema).

SUMMARY OF THE INVENTION

The present invention is directed to interfering RNAs that silence HIF1AmRNA expression, thus decreasing transcriptional activity of HIF-1inducible genes and treating ocular angiogenesis by effecting a loweringof ocular pre-angiogenic and angiogenic cellular activity.

The term “ocular angiogenesis,” as used herein, includes ocularpre-angiogenic conditions and ocular angiogenic conditions, and includesthose cellular changes resulting from the expression of HIF1-induciblegenes that lead directly or indirectly to ocular angiogenesis, ocularneovasularization, retinal edema, diabetic retinopathy, sequelaassociated with retinal ischemia, PSNV, and neovascular glaucoma, forexample. The interfering RNAs of the invention are useful for treatingpatients with ocular angiogenesis, ocular neovasularization, retinaledema, diabetic retinopathy, sequela associated with retinal ischemia,posterior segment neovascularization (PSNV), and neovascular glaucoma,or patients at risk of developing such conditions, for example.

An embodiment of the present invention provides a method of attenuatingexpression of an HIF1A target mRNA in a subject. The method comprisesadministering to the subject a composition comprising an effectiveamount of interfering RNA having a length of 19 to 49 nucleotides and apharmaceutically acceptable carrier. In one embodiment, administrationis to an eye of the subject for attenuating expression of an ocularangiogenesis target in a human.

In one embodiment of the invention, the interfering RNA comprises asense nucleotide strand, an antisense nucleotide strand and a region ofat least near-perfect contiguous complementarity of at least 19nucleotides. Further, the antisense strand hybridizes underphysiological conditions to a portion of an mRNA corresponding to SEQ IDNO:1 or SEQ ID NO:2 which are the sense cDNA sequences encoding HIF1Avariant 1 and variant 2, respectively (GenBank accession no. NM_001530and NM_181054, respectively). The antisense strand has a region of atleast near-perfect contiguous complementarity of at least 19 nucleotideswith the hybridizing portion of mRNA corresponding to SEQ ID NO:1 or SEQID NO:2, respectively. The administration of such a compositionattenuates the expression of an HIF1A target of the subject.

In one embodiment of the invention, an interfering RNA is designed totarget an mRNA corresponding to SEQ ID NO:1 comprising nucleotide 411,580, 583, 868, 869, 1099, 1100, 1242, 1302, 1371, 1396, 1559, 1560,1809, 2085, 2087, 2105, 2138, 2256, 2358, 2422, 2636, 2666, 2743, 2858,2861, 3135, 3544, 3554, 1943, 1791, 2351, or 1408.

In another embodiment of the invention, an interfering RNA is designedto target an mRNA corresponding to SEQ ID NO:2 comprising nucleotide2360, 2411, 2420, 2536, 2539, 2545, 2616, 2731, 2734, 3008, or 3427.

The present invention further provides for administering a secondinterfering RNA to a subject in addition to a first interfering RNA. Themethod comprises administering to the subject a second interfering RNAhaving a length of 19 to 49 nucleotides and comprising a sensenucleotide strand, an antisense nucleotide strand, and a region of atleast near-perfect contiguous complementarity of at least 19nucleotides; wherein the antisense strand of the second interfering RNAhybridizes under physiological conditions to a second portion of mRNAcorresponding to SEQ ID NO:1 or SEQ ID NO:2 and the antisense strand hasa region of at least near-perfect contiguous complementarity of at least19 nucleotides with the second hybridizing portion of mRNA correspondingto SEQ ID NO:1 or SEQ ID NO:2, respectively. Further, a third, fourth,or fifth, etc. interfering RNA may be administered in a similar manner.

Another embodiment of the invention is a method of attenuatingexpression of HIF1A in a subject comprising administering to the subjecta composition comprising an effective amount of single-strandedinterfering RNA having a length of 19 to 49 nucleotides and apharmaceutically acceptable carrier.

For attenuating expression of HIF1A, the single-stranded interfering RNAhybridizes under physiological conditions to a portion of mRNAcorresponding to SEQ ID NO:1 comprising nucleotide 411, 580, 583, 868,869, 1099, 1100, 1242, 1302, 1371, 1396, 1559, 1560, 1809, 2085, 2087,2105, 2138, 2256, 2358, 2422, 2636, 2666, 2743, 2858, 2861, 3135, 3544,3554, 1943, 1791, 2351, or 1408, and the interfering RNA has a region ofat least near-perfect contiguous complementarity of at least 19nucleotides with the hybridizing portion of mRNA corresponding to SEQ IDNO:1. In another embodiment , for attenuating expression of HIF1A, thesingle-stranded interfering RNA hybridizes under physiologicalconditions to a portion of mRNA corresponding to SEQ ID NO:2 comprisingnucleotide 2360, 2411, 2420, 2536, 2539, 2545, 2616, 2731, 2734, 3008,or 3427. Expression of HIF1A is thereby attenuated.

A further embodiment of the invention is a method of treating ocularangiogenesis in a subject in need thereof. The method comprisesadministering to an eye of the subject a composition comprising aneffective amount of interfering RNA having a length of 19 to 49nucleotides and a pharmaceutically acceptable carrier, the interferingRNA comprising a sense nucleotide strand, an antisense nucleotidestrand, and a region of at least near-perfect contiguous complementarityof at least 19 nucleotides. The antisense strand hybridizes underphysiological conditions to a portion of mRNA corresponding to SEQ IDNO:1 or SEQ ID NO:2 and has a region of at least near-perfect contiguouscomplementarity of at least 19 nucleotides with the hybridizing portionof mRNA corresponding to SEQ ID NO:1 or SEQ ID NO:2, respectively. Theocular angiogenesis is treated thereby.

Another embodiment of the invention is a method of treating ocularangiogenesis in a subject in need thereof, the method comprisingadministering to an eye of the subject a composition comprising aneffective amount of interfering RNA having a length of 19 to 49nucleotides and a pharmaceutically acceptable carrier, the interferingRNA comprising a region of at least 13 contiguous nucleotides having atleast 90% sequence complementarity to, or at least 90% sequence identitywith, the penultimate 13 nucleotides of the 3′ end of an mRNAcorresponding to any one of SEQ ID NO:3 and SEQ ID NO:9-SEQ ID NO:51,wherein the ocular angiogenesis is treated thereby.

Another embodiment of the invention is a method of attenuatingexpression of an HIF1A target mRNA in a subject, comprisingadministering to the subject a composition comprising an effectiveamount of interfering RNA having a length of 19 to 49 nucleotides and apharmaceutically acceptable carrier, where the interfering RNA comprisesa region of at least 13 contiguous nucleotides having at least 90%sequence complementarity to, or at least 90% sequence identity with, thepenultimate 13 nucleotides of the 3′ end of an mRNA corresponding to anyone of SEQ ID NO:3 and SEQ ID NO:9-SEQ ID NO:51.

In a further embodiment of the present invention, the region ofcontiguous nucleotides is a region of at least 14 contiguous nucleotideshaving at least 85% sequence complementarity to, or at least 85%sequence identity with, the penultimate 14 nucleotides of the 3′ end ofan mRNA corresponding to the sequence of the sequence identifier. In yetanother embodiment of the invention, the region of contiguousnucleotides is a region of at least 15, 16, 17, or 18 contiguousnucleotides having at least 80% sequence complementarity to, or at least80% sequence identity with, the penultimate 15, 16, 17, or 18nucleotides, respectively, of the 3′ end of an mRNA corresponding to thesequence identified by the sequence identifier.

A further embodiment of the invention is a method of treating ocularangiogenesis in a subject in need thereof, the method comprisingadministering to the subject a composition comprising a double strandedsiRNA molecule that down regulates expression of a HIF1A gene via RNAinterference, wherein each strand of the siRNA molecule is independentlyabout 19 to about 27 nucleotides in length; and one strand of the siRNAmolecule comprises a nucleotide sequence having substantialcomplementarity to an mRNA corresponding to the HIF1A gene,respectively, so that the siRNA molecule directs cleavage of the mRNAvia RNA interference.

A composition comprising interfering RNA having a length of 19 to 49nucleotides and having a nucleotide sequence of any one of SEQ ID NO:3,and SEQ ID NO:9-SEQ ID NO:51, or a complement thereof, and apharmaceutically acceptable carrier is an embodiment of the presentinvention. In one embodiment, the interfering RNA is isolated. The term“isolated” means that the interfering RNA is free of its total naturalmileau.

Another embodiment of the invention is a composition comprising a doublestranded siRNA molecule that down regulates expression of a HIF1A genevia RNA interference, wherein each strand of the siRNA molecule isindependently about 19 to about 27 nucleotides in length; and one strandof the siRNA molecule comprises a nucleotide sequence has substantialcomplementarity to an mRNA corresponding to the HIF1A gene,respectively, so that the siRNA molecule directs cleavage of the mRNAvia RNA interference.

Use of any of the embodiments as described herein in the preparation ofa medicament for attenuating expression of HIF1A mRNA is also anembodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWING

The FIGURE provides a HIF-1α western blot of HeLa cells transfected withHIF1A siRNAs #1, #3, #5, and #6, and a RISC-free control siRNA, each at10 nM, 1 nM, and 0.1 nM; a non-targeting control siRNA (NTC2) at 10 nM;and a buffer control (-siRNA). The arrows indicate the positions of the93-kDa HIF-1α protein and the 42-kDa actin protein bands.

DETAILED DESCRIPTION OF THE INVENTION

RNA interference (RNAi) is a process by which double-stranded RNA(dsRNA) is used to silence gene expression. While not wanting to bebound by theory, RNAi begins with the cleavage of longer dsRNAs intosmall interfering RNAs (siRNAs) by an RNaseIII-like enzyme, dicer.SiRNAs are dsRNAs that are usually about 19 to 28 nucleotides, or 20 to25 nucleotides, or 21 to 22 nucleotides in length and often contain2-nucleotide 3′ overhangs, and 5′ phosphate and 3′ hydroxyl termini. Onestrand of the siRNA is incorporated into a ribonucleoprotein complexknown as the RNA-induced silencing complex (RISC). RISC uses this siRNAstrand to identify mRNA molecules that are at least partiallycomplementary to the incorporated siRNA strand, and then cleaves thesetarget mRNAs or inhibits their translation. Therefore, the siRNA strandthat is incorporated into RISC is known as the guide strand or theantisense strand. The other siRNA strand, known as the passenger strandor the sense strand, is eliminated from the siRNA and is at leastpartially homologous to the target mRNA. Those of skill in the art willrecognize that, in principle, either strand of an siRNA can beincorporated into RISC and function as a guide strand. However, siRNAdesign (e.g., decreased siRNA duplex stability at the 5′ end of theantisense strand) can favor incorporation of the antisense strand intoRISC.

RISC-mediated cleavage of mRNAs having a sequence at least partiallycomplementary to the guide strand leads to a decrease in the steadystate level of that mRNA and of the corresponding protein encoded bythis mRNA. Alternatively, RISC can also decrease expression of thecorresponding protein via translational repression without cleavage ofthe target mRNA. Other RNA molecules and RNA-like molecules can alsointeract with RISC and silence gene expression. Examples of other RNAmolecules that can interact with RISC include short hairpin RNAs(shRNAs), single-stranded siRNAs, microRNAs (miRNAs), anddicer-substrate 27-mer duplexes. The term “siRNA” as used herein refersto a double-stranded interfering RNA unless otherwise noted. Examples ofRNA-like molecules that can interact with RISC include RNA moleculescontaining one or more chemically modified nucleotides, one or moredeoxyribonucleotides, and/or one or more non-phosphodiester linkages.For purposes of the present discussion, all RNA or RNA-like moleculesthat can interact with RISC and participate in RISC-mediated changes ingene expression will be referred to as “interfering RNAs.” SiRNAs,shRNAs, miRNAs, and dicer-substrate 27-mer duplexes are, therefore,subsets of “interfering RNAs.”

Interfering RNA of embodiments of the invention appear to act in acatalytic manner for cleavage of target mRNA, i.e., interfering RNA isable to effect inhibition of target mRNA in substoichiometric amounts.As compared to antisense therapies, significantly less interfering RNAis required to provide a therapeutic effect under such cleavageconditions.

The present invention relates to the use of interfering RNA to inhibitthe expression of hypoxia-inducible factor 1A (HIF1A), thus interferingwith transcription of a number of genes that would otherwise be inducedin response to reduced oxygen tension. According to the presentinvention, interfering RNAs as set forth herein, provided exogenously orexpressed endogenously, are particularly effective at silencing of HIF1AmRNA.

Nucleic acid sequences cited herein are written in a 5′ to 3′ directionunless indicated otherwise. The term “nucleic acid,” as used herein,refers to either DNA or RNA or a modified form thereof comprising thepurine or pyrimidine bases present in DNA (adenine “A,” cytosine “C,”guanine “G,” thymine “T”) or in RNA (adenine “A,” cytosine “C,” guanine“G,” uracil “U”). Interfering RNAs provided herein may comprise “T”bases, particularly at 3′ ends, even though “T” bases do not naturallyoccur in RNA. “Nucleic acid” includes the terms “oligonucleotide” and“polynucleotide” and can refer to a single-stranded molecule or adouble-stranded molecule. A double-stranded molecule is formed byWatson-Crick base pairing between A and T bases, C and G bases, andbetween A and U bases. The strands of a double-stranded molecule mayhave partial, substantial or full complementarity to each other and willform a duplex hybrid, the strength of bonding of which is dependent uponthe nature and degree of complementarity of the sequence of bases.

An mRNA sequence is readily deduced from the sequence of thecorresponding DNA sequence. For example, SEQ ID NO:1 provides the sensestrand sequence of DNA corresponding to the mRNA for HIF1A variant 1.The mRNA sequence is identical to the DNA sense strand sequence with the“T” bases replaced with “U” bases. Therefore, the mRNA sequence of HIF1Avariant 1 is known from SEQ ID NO:1 and the mRNA sequence of HIF1Avariant 2 is known from SEQ ID NO:2.

Hypoxia-Inducible Factor-1 mRNA (HIF1A variant 1 and variant 2):Hypoxia-inducible factor (HIF-1) is a transcription factor that isresponsible for changes in expression in a number of genes in responseto reduced oxygen tension. HIF-1 is a heterodimer composed of alpha andbeta subunits encoded by HIF1A and ARNT, respectively. At least twoHIF-1-inducible genes have been implicated in pathologicalneovascularization in the retina including VEGF and RTP801 (REDD1).Therefore, inhibition of expression of HIF1A is provided herein toattenuate transcription of such genes and activity of the gene products.

The GenBank database of the National Center for BiotechnologyInformation at ncbi.nlm.nih.gov provides the DNA sequence for HIF1Avariant 1 as accession no. NM_001530, provided in the “Sequence Listing”as SEQ ID NO:1. SEQ ID NO:1 provides the sense strand sequence of DNAthat corresponds to the mRNA encoding HIF1A variant 1 (with theexception of “T” bases for “U” bases). The coding sequence for HIF1Avariant 1 is from nucleotides 285-2765.

Equivalents of the above-cited HIF1A variant 1 mRNA sequence arealternative splice forms, allelic forms, isozymes, or a cognate thereof.A cognate is an HIF1A mRNA from another mammalian species that ishomologous to SEQ ID NO:1 (an ortholog).

The GenBank database of the National Center for BiotechnologyInformation at ncbi.nlm.nih.gov provides the DNA sequence for HIF1Avariant 2 as accession no. NM_181054, provided in the “Sequence Listing”as SEQ ID NO:2. SEQ ID NO:2 provides the sense strand sequence of DNAthat corresponds to the mRNA encoding HIF1A variant 2 (with theexception of “T” bases for “U” bases). The coding sequence for HIF1Avariant 2 is from nucleotides 285-2492.

Equivalents of the above-cited HIF1A variant 2 mRNA sequence arealternative splice forms, allelic forms, isozymes, or a cognate thereof.A cognate is an HIF1A variant 2 mRNA from another mammalian species thatis homologous to SEQ ID NO:2 (an ortholog).

Attenuating expression of an mRNA: The phrase, “attenuating expressionof an mRNA,” as used herein, means administering or expressing an amountof interfering RNA (e.g., an siRNA) to reduce translation of the targetmRNA into protein, either through mRNA cleavage or through directinhibition of translation. The reduction in expression of the targetmRNA or the corresponding protein is commonly referred to as“knock-down” and is reported relative to levels present followingadministration or expression of a non-targeting control RNA (e.g., anon-targeting control siRNA). Knock-down of expression of an amountincluding and between 50% and 100% is contemplated by embodimentsherein. However, it is not necessary that such knock-down levels beachieved for purposes of the present invention. In one embodiment, asingle interfering RNA targeting the HIF1A mRNA is administered todecrease production of HIF1A. In other embodiments, two or moreinterfering RNAs targeting the HIF1A target are administered to decreaseexpression. In still other embodiments, a first interfering RNAtargeting the HIF1A variant 1 target and a second interfering RNAtargeting the HIF1A variant 2 target are administered to decrease HIF1Aexpression.

Knock-down is commonly assessed by measuring the mRNA levels usingquantitative polymerase chain reaction (qPCR) amplification or bymeasuring protein levels by western blot or enzyme-linked immunosorbentassay (ELISA). Analyzing the protein level provides an assessment ofboth mRNA cleavage as well as translation inhibition. Further techniquesfor measuring knock-down include RNA solution hybridization, nucleaseprotection, northern hybridization, gene expression monitoring with amicroarray, antibody binding, radioimmunoassay, and fluorescenceactivated cell analysis.

Inhibition of targets cited herein is also inferred in a human or mammalby observing an improvement in an ocular angiogenesis symptom such asimprovement in retinal edema, diabetic retinopathy, retinal ischemia, orin posterior segment neovascularization (PSNV), for example.

Interfering RNA: In one embodiment of the invention, interfering RNA(e.g., siRNA) has a sense strand and an antisense strand, and the senseand antisense strands comprise a region of at least near-perfectcontiguous complementarity of at least 19 nucleotides. In a furtherembodiment of the invention, interfering RNA (e.g., siRNA) has a sensestrand and an antisense strand, and the antisense strand comprises aregion of at least near-perfect contiguous complementarity of at least19 nucleotides to a target sequence of HIF1A mRNA, and the sense strandcomprises a region of at least near-perfect contiguous identity of atleast 19 nucleotides with a target sequence of HIF1A mRNA, respectively.In a further embodiment of the invention, the interfering RNA comprisesa region of at least 13, 14, 15, 16, 17, or 18 contiguous nucleotideshaving percentages of sequence complementarity to or, having percentagesof sequence identity with, the penultimate 13, 14, 15, 16, 17, or 18nucleotides, respectively, of the 3′ end of the corresponding targetsequence within an mRNA.

The length of each strand of the interfering RNA comprises 19 to 49nucleotides, and may comprise a length of 19, 20, 21, 22, 23, 24, 25,26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43,44, 45, 46, 47, 48, or 49 nucleotides.

The antisense strand of an siRNA is the active guiding agent of thesiRNA in that the antisense strand is incorporated into RISC, thusallowing RISC to identify target mRNAs with at least partialcomplementary to the antisense siRNA strand for cleavage ortranslational repression.

In embodiments of the present invention, interfering RNA targetsequences (e.g., siRNA target sequences) within a target mRNA sequenceare selected using available design tools. Interfering RNAscorresponding to a HIF1A target sequence are then tested by transfectionof cells expressing the target mRNA followed by assessment of knockdownas described above.

Techniques for selecting target sequences for siRNAs are provided byTuschl, T. et al., “The siRNA User Guide,” revised May 6, 2004,available on the Rockefeller University web site; by Technical Bulletin#506, “siRNA Design Guidelines,” Ambion Inc. at Ambion's web site; andby other web-based design tools at, for example, the Invitrogen,Dharmacon, Integrated DNA Technologies, Genscript, or Proligo web sites.Initial search parameters can include G/C contents between 35% and 55%and siRNA lengths between 19 and 27 nucleotides. The target sequence maybe located in the coding region or in the 5′ or 3′ untranslated regionsof the mRNA.

An embodiment of a 19-nucleotide DNA target sequence common to HIF1Avariant 1 and HIV1A variant 2 is present at nucleotides 411 to 429 ofSEQ ID NO:1:

SEQ ID NO: 3 5′-CAGTTGCCACTTCCACATA-3′.

An siRNA of the invention for targeting a corresponding mRNA sequence ofSEQ ID NO:3 and having 21-nucleotide strands and a 2-nucleotide 3′overhang is:

SEQ ID NO: 4 5′-CAGUUGCCACUUCCACAUANN-3′ SEQ ID NO: 53′-NNGUCAACGGUGAAGGUGUAU-5′.

Each “N” residue can be any nucleotide (A, C, G, U, T) or modifiednucleotide. The 3′ end can have a number of “N” residues between andincluding 1, 2, 3, 4, 5, and 6. The “N” residues on either strand can bethe same residue (e.g., UU, AA, CC, GG, or TT) or they can be different(e.g., AC, AG, AU, CA, CG, CU, GA, GC, GU, UA, UC, or UG). The 3′overhangs can be the same or they can be different. In one embodiment,both strands have a 3′UU overhang.

An siRNA of the invention for targeting a corresponding mRNA sequence ofSEQ ID NO:3 and having 21-nucleotide strands and a 3′UU overhang on eachstrand is:

SEQ ID NO: 6 5′-CAGUUGCCACUUCCACAUAUU-3′ SEQ ID NO: 73′-UUGUCAACGGUGAAGGUGUAU-5′.

The interfering RNA may also have a 5′ overhang of nucleotides or it mayhave blunt ends. An siRNA of the invention for targeting a correspondingmRNA sequence of SEQ ID NO:3 and having 19-nucleotide strands and bluntends is:

SEQ ID NO: 52 5′-CAGUUGCCACUUCCACAUA-3′ SEQ ID NO: 533′-GUCAACGGUGAAGGUGUAU-5′.

The strands of a double-stranded interfering RNA (e.g., an siRNA) may beconnected to form a hairpin or stem-loop structure (e.g., an shRNA). AnshRNA of the invention targeting a corresponding mRNA sequence of SEQ IDNO:1 and having a 19 bp double-stranded stem region and a 3′UU overhangis:

N is a nucleotide A, T, C, G, U, or a modified form known by one ofordinary skill in the art. The number of nucleotides N in the loop is anumber between and including 3 to 23, or 5 to 15, or 7 to 13, or 4 to 9,or 9 to 11, or the number of nucleotides N is 9. Some of the nucleotidesin the loop can be involved in base-pair interactions with othernucleotides in the loop. Examples of oligonucleotide sequences that canbe used to form the loop include 5′-UUCAAGAGA-3′ (Brummelkamp, T. R. etal. (2002) Science 296: 550) and 5′-UUUGUGUAG-3′ (Castanotto, D. et al.(2002) RNA 8:1454). It will be recognized by one of skill in the artthat the resulting single chain oligonucleotide forms a stem-loop orhairpin structure comprising a double-stranded region capable ofinteracting with the RNAi machinery.

The siRNA target sequence identified above can be extended at the 3′ endto facilitate the design of dicer-substrate 27-mer duplexes. Extensionof the 19-nucleotide DNA target sequence (SEQ ID NO:3) identified in theHIF1A DNA sequence (SEQ ID NO:1) by 6 nucleotides yields a 25-nucleotideDNA target sequence present at nucleotides 411 to 435 of SEQ ID NO:1:

SEQ ID NO: 54 5′-CAGTTGCCACTTCCACATAATGTGA-3′.

A dicer-substrate 27-mer duplex of the invention for targeting acorresponding mRNA sequence of SEQ ID NO:54 is:

SEQ ID NO: 55 5′-CAGUUGCCACUUCCACAUAAUGUGA-3′ SEQ ID NO: 563′-UUGUCAACGGUGAAGGUGUAUUACACU-5′.

The two nucleotides at the 3′ end of the sense strand (i.e., the GAnucleotides of SEQ ID NO:55) may be deoxynucleotides for enhancedprocessing. Design of dicer-substrate 27-mer duplexes from 19-21nucleotide target sequences, such as provided herein, is furtherdiscussed by the Integrated DNA Technologies (IDT) website and by Kim,D.-H. et al., (February, 2005) Nature Biotechnology 23:2; 222-226.

When interfering RNAs are produced by chemical synthesis,phosphorylation at the 5′ position of the nucleotide at the 5′ end ofone or both strands (when present) can enhance siRNA efficacy andspecificity of the bound RISC complex but is not required sincephosphorylation can occur intracellularly.

Table 1 lists examples of HIF1A variant 1 and variant 2 DNA targetsequences of SEQ ID NO:1 and SEQ ID NO:2, respectively, from whichsiRNAs of the present invention are designed in a manner as set forthabove. HIF1A encodes hypoxia-inducible factor 1 alpha, as noted above.

TABLE 1 HIF1A Target Sequences for siRNAs # of StartingHIF1A variant 1 and Nucleotide with variant 2 Target reference toSequences in Common SEQ ID NO: 1 SEQ ID NO: CAGTTGCCACTTCCACATA 411 3TTGTTATGGTTCTCACAGA 580 9 TTATGGTTCTCACAGATGA 583 10 CAGGCCACATTCACGTATA868 11 AGGCCACATTCACGTATAT 869 12 GCCGCTCAATTTATGAATA 1099 13CCGCTCAATTTATGAATAT 1100 14 CAAGCAACTGTCATATATA 1242 15TACGTTGTGAGTGGTATTA 1302 16 CCGGTTGAATCTTCAGATA 1371 17TGACTCAGCTATTCACCAA 1396 18 TGAGGAAGTACCATTATAT 1559 19GAGGAAGTACCATTATATA 1560 20 AGTTCACCTGAGCCTAATA 1809 21GTATTCCAGCAGACTCAAA 2085 22 ATTCCAGCAGACTCAAATA 2087 23ACAAGAACCTACTGCTAAT 2105 24 TGCCACCACTGATGAATTA 2138 25CCATATAGAGATACTCAAA 2256 26 TCTGTCGCTTTGAGTCAAA 2358 27TGCAGAATGCTCAGAGAAA 2422 28 GGACACAGATTTAGACTTG 1943 48GATGGAAGCACTAGACAAA 1791 49 CGTGTTATCTGTCGCTTTG 2351 50TCACCAAAGTTGAATCAGA 1408 51 # of Starting Nucleotide withHIF1A variant 1 reference to Target Sequence SEQ ID NO: 1 SEQ ID NO:GCAATCAATGGATGAAAGT 2636 29 GCTGACCAGTTATGATTGT 2666 30GAGCTTTGGATCAAGTTAA 2743 31 TGGCTACAATACTGCACAA 2858 32CTACAATACTGCACAAACT 2861 33 ATGATCATAGGCAGTTGAA 3135 34CTATGTAGTTGTGGAAGTT 3544 35 GTGGAAGTTTATGCTAATA 3554 36 # of StartingNucleotide with HIF1A variant 2 reference to Target SequenceSEQ ID NO: 2 SEQ ID NO: TGTCGCTTTGAGTCAAAGA 2360 37 GATACTAGCTTTGCAGAAT2411 38 TTTGCAGAATGCTCAGAGA 2420 39 ACAGCTGACCAGTTATGAT 2536 40GCTGACCAGTTATGATTGT 2539 41 CAGTTATGATTGTGAAGTT 2545 42GAGCTTTGGATCAAGTTAA 2616 43 TGGCTACAATACTGCACAA 2731 44CTACAATACTGCACAAACT 2734 45 ATGATCATAGGCAGTTGAA 3008 46GTGGAAGTTTATGCTAATA 3427 47

As cited in the examples above, one of skill in the art is able to usethe target sequence information provided in Table 1 to designinterfering RNAs having a length shorter or longer than the sequencesprovided in the table and by referring to the sequence position in SEQID NO:1 or SEQ ID NO:2 and adding or deleting nucleotides complementaryor near complementary to SEQ ID NO:1 or SEQ ID NO:2 respectively.

The target RNA cleavage reaction guided by siRNAs and other forms ofinterfering RNA is highly sequence specific. In general, siRNAcontaining a sense nucleotide strand identical in sequence to a portionof the target mRNA and an antisense nucleotide strand exactlycomplementary to a portion of the target mRNA are siRNA embodiments forinhibition of mRNAs cited herein. However, 100% sequence complementaritybetween the antisense siRNA strand and the target mRNA, or between theantisense siRNA strand and the sense siRNA strand, is not required topractice the present invention. Thus, for example, the invention allowsfor sequence variations that might be expected due to genetic mutation,strain polymorphism, or evolutionary divergence.

In one embodiment of the invention, the antisense strand of the siRNAhas at least near-perfect contiguous complementarity of at least 19nucleotides with the target mRNA. “Near-perfect,” as used herein, meansthe antisense strand of the siRNA is “substantially complementary to,”and the sense strand of the siRNA is “substantially identical to” atleast a portion of the target mRNA. “Identity,” as known by one ofordinary skill in the art, is the degree of sequence relatedness betweennucleotide sequences as determined by matching the order and identity ofnucleotides between the sequences. In one embodiment, the antisensestrand of an siRNA having 80% and between 80% up to 100%complementarity, for example, 85%, 90% or 95% complementarity, to thetarget mRNA sequence are considered near-perfect complementarity and maybe used in the present invention. “Perfect” contiguous complementarityis standard Watson-Crick base pairing of adjacent base pairs. “At leastnear-perfect” contiguous complementarity includes “perfect”complementarity as used herein. Computer methods for determiningidentity or complementarity are designed to identify the greatest degreeof matching of nucleotide sequences, for example, BLASTN (Altschul, S.F., et al. (1990) J. Mol. Biol. 215:403-410).

The term “percent identity” describes the percentage of contiguousnucleotides in a first nucleic acid molecule that is the same as in aset of contiguous nucleotides of the same length in a second nucleicacid molecule. The term “percent complementarity” describes thepercentage of contiguous nucleotides in a first nucleic acid moleculethat can base pair in the Watson-Crick sense with a set of contiguousnucleotides in a second nucleic acid molecule.

The relationship between a target mRNA (sense strand) and one strand ofan siRNA (the sense strand) is that of identity. The sense strand of ansiRNA is also called a passenger strand, if present. The relationshipbetween a target mRNA (sense strand) and the other strand of an siRNA(the antisense strand) is that of complementarity. The antisense strandof an siRNA is also called a guide strand.

The penultimate base in a nucleic acid sequence that is written in a 5′to 3′ direction is the next to the last base, i.e., the base next to the3′ base. The penultimate 13 bases of a nucleic acid sequence written ina 5′ to 3′ direction are the last 13 bases of a sequence next to the 3′base and not including the 3′ base. Similarly, the penultimate 14, 15,16, 17, or 18 bases of a nucleic acid sequence written in a 5′ to 3′direction are the last 14, 15, 16, 17, or 18 bases of a sequence,respectively, next to the 3′ base and not including the 3′ base.

The phrase “a region of at least 13 contiguous nucleotides having atleast 90% sequence complementarity to, or at least 90% sequence identitywith, the penultimate 13 nucleotides of the 3′ end of an mRNAcorresponding to any one of (a sequence identifier)” allows a onenucleotide substitution. Two nucleotide substitutions (i.e., 11/13=85%identity/complementarity) are not included in such a phrase.

In one embodiment of the invention, the region of contiguous nucleotidesis a region of at least 14 contiguous nucleotides having at least 85%sequence complementarity to, or at least 85% sequence identity with, thepenultimate 14 nucleotides of the 3′ end of an mRNA corresponding to thesequence identified by each sequence identifier. Two nucleotidesubstitutions (i.e., 12/14=86% identity/complementarity) are included insuch a phrase.

In a further embodiment of the invention, the region of contiguousnucleotides is a region of at least 15, 16, 17, or 18 contiguousnucleotides having at least 80% sequence complementarity to, or at least80% sequence identity with, the penultimate 14 nucleotides of the 3′ endof an mRNA corresponding to the sequence of the sequence identifier.Three nucleotide substitutions are included in such a phrase.

The target sequence in the mRNAs corresponding to SEQ ID NO:1 or SEQ IDNO:2 may be in the 5′ or 3′ untranslated regions of the mRNA as well asin the coding region of the mRNA.

One or both of the strands of double-stranded interfering RNA may have a3′ overhang of from 1 to 6 nucleotides, which may be ribonucleotides ordeoxyribonucleotides or a mixture thereof. The nucleotides of theoverhang are not base-paired. In one embodiment of the invention, theinterfering RNA comprises a 3′ overhang of TT or UU. In anotherembodiment of the invention, the interfering RNA comprises at least oneblunt end. The termini usually have a 5′ phosphate group or a 3′hydroxyl group. In other embodiments, the antisense strand has a 5′phosphate group, and the sense strand has a 5′ hydroxyl group. In stillother embodiments, the termini are further modified by covalent additionof other molecules or functional groups.

The sense and antisense strands of the double-stranded siRNA may be in aduplex formation of two single strands as described above or may be asingle molecule where the regions of complementarity are base-paired andare covalently linked by a hairpin loop so as to form a single strand.It is believed that the hairpin is cleaved intracellularly by a proteintermed dicer to form an interfering RNA of two individual base-pairedRNA molecules.

Interfering RNAs may differ from naturally-occurring RNA by theaddition, deletion, substitution or modification of one or morenucleotides. Non-nucleotide material may be bound to the interferingRNA, either at the 5′ end, the 3′ end, or internally. Such modificationsare commonly designed to increase the nuclease resistance of theinterfering RNAs, to improve cellular uptake, to enhance cellulartargeting, to assist in tracing the interfering RNA, to further improvestability, or to reduce the potential for activation of the interferonpathway. For example, interfering RNAs may comprise a purine nucleotideat the ends of overhangs. Conjugation of cholesterol to the 3′ end ofthe sense strand of an siRNA molecule by means of a pyrrolidine linker,for example, also provides stability to an siRNA. [0001] Furthermodifications include a 3′ terminal biotin molecule, a peptide known tohave cell-penetrating properties, a nanoparticle, a peptidomimetic, afluorescent dye, or a dendrimer, for example.

Nucleotides may be modified on their base portion, on their sugarportion, or on the phosphate portion of the molecule and function inembodiments of the present invention. Modifications includesubstitutions with alkyl, alkoxy, amino, deaza, halo, hydroxyl, thiolgroups, or a combination thereof, for example. Nucleotides may besubstituted with analogs with greater stability such as replacing aribonucleotide with a deoxyribonucleotide, or having sugar modificationssuch as 2′ OH groups replaced by 2′ amino groups, 2′ O-methyl groups, 2′methoxyethyl groups, or a 2′-O, 4′-C methylene bridge, for example.Examples of a purine or pyrimidine analog of nucleotides include axanthine, a hypoxanthine, an azapurine, a methylthioadenine,7-deaza-adenosine and O- and N-modified nucleotides. The phosphate groupof the nucleotide may be modified by substituting one or more of theoxygens of the phosphate group with nitrogen or with sulfur(phosphorothioates). Modifications are useful, for example, to enhancefunction, to improve stability or permeability, or to directlocalization or targeting.

There may be a region or regions of the antisense interfering RNA strandthat is (are) not complementary to a portion of SEQ ID NO:1 or SEQ IDNO:2. Non-complementary regions may be at the 3′, 5′ or both ends of acomplementary region or between two complementary regions.

Interfering RNAs may be generated exogenously by chemical synthesis, byin vitro transcription, or by cleavage of longer double-stranded RNAwith dicer or another appropriate nuclease with similar activity.Chemically synthesized interfering RNAs, produced from protectedribonucleoside phosphoramidites using a conventional DNA/RNAsynthesizer, may be obtained from commercial suppliers such as AmbionInc. (Austin, Tex.), Invitrogen (Carlsbad, Calif.), or Dharmacon(Lafayette, Colo.). Interfering RNAs are purified by extraction with asolvent or resin, precipitation, electrophoresis, chromatography, or acombination thereof, for example. Alternatively, interfering RNA may beused with little if any purification to avoid losses due to sampleprocessing.

Interfering RNAs can also be expressed endogenously from plasmid orviral expression vectors or from minimal expression cassettes, forexample, PCR generated fragments comprising one or more promoters and anappropriate template or templates for the interfering RNA. Examples ofcommercially available plasmid-based expression vectors for shRNAinclude members of the pSilencer series (Ambion, Austin, Tex.) andpCpG-siRNA (InvivoGen, San Diego, Calif.). Viral vectors for expressionof interfering RNA may be derived from a variety of viruses includingadenovirus, adeno-associated virus, lentivirus (e.g., HIV, FIV, andEIAV), and herpes virus. Examples of commercially available viralvectors for shRNA expression include pSilencer adeno (Ambion, Austin,Tex.) and pLenti6/BLOCK-iT™-DEST (Invitrogen, Carlsbad, Calif.).Selection of viral vectors, methods for expressing the interfering RNAfrom the vector and methods of delivering the viral vector are withinthe ordinary skill of one in the art. Examples of kits for production ofPCR-generated shRNA expression cassettes include Silencer Express(Ambion, Austin, Tex.) and siXpress (Minis, Madison, Wis.). A firstinterfering RNA may be administered via in vivo expression from a firstexpression vector capable of expressing the first interfering RNA and asecond interfering RNA may be administered via in vivo expression from asecond expression vector capable of expressing the second interferingRNA, or both interfering RNAs may be administered via in vivo expressionfrom a single expression vector capable of expressing both interferingRNAs.

Interfering RNAs may be expressed from a variety of eukaryotic promotersknown to those of ordinary skill in the art, including pol IIIpromoters, such as the U6 or H1 promoters, or pol II promoters, such asthe cytomegalovirus promoter. Those of skill in the art will recognizethat these promoters can also be adapted to allow inducible expressionof the interfering RNA.

Hybridization under Physiological Conditions: In certain embodiments ofthe present invention, an antisense strand of an interfering RNAhybridizes with an mRNA in vivo as part of the RISC complex.

“Hybridization” refers to a process in which single-stranded nucleicacids with complementary or near-complementary base sequences interactto form hydrogen-bonded complexes called hybrids. Hybridizationreactions are sensitive and selective. In vitro, the specificity ofhybridization (i.e., stringency) is controlled by the concentrations ofsalt or formamide in prehybridization and hybridization solutions, forexample, and by the hybridization temperature; such procedures are wellknown in the art. In particular, stringency is increased by reducing theconcentration of salt, increasing the concentration of formamide, orraising the hybridization temperature.

For example, high stringency conditions could occur at about 50%formamide at 37° C. to 42° C. Reduced stringency conditions could occurat about 35% to 25% formamide at 30° C. to 35° C. Examples of stringencyconditions for hybridization are provided in Sambrook, J., 1989,Molecular Cloning: A Laboratory Manual, Cold Spring Harbor LaboratoryPress, Cold Spring Harbor, N.Y. Further examples of stringenthybridization conditions include 400 mM NaCl, 40 mM PIPES pH 6.4, 1 mMEDTA, 50° C. or 70° C. for 12-16 hours followed by washing, orhybridization at 70° C. in 1×SSC or 50° C. in 1×SSC, 50% formamidefollowed by washing at 70° C. in 0.3×SSC, or hybridization at 70° C. in4×SSC or 50° C. in 4×SSC, 50% formamide followed by washing at 67° C. in1×SSC. The temperature for hybridization is about 5-10° C. less than themelting temperature (T_(m)) of the hybrid where T_(m) is determined forhybrids between 19 and 49 base pairs in length using the followingcalculation: T_(m)° C.=81.5+16.6(log₁₀[Na+])+0.41 (% G+C)−(600/N) whereN is the number of bases in the hybrid, and [Na+] is the concentrationof sodium ions in the hybridization buffer.

The above-described in vitro hybridization assay provides a method ofpredicting whether binding between a candidate siRNA and a target willhave specificity. However, in the context of the RISC complex, specificcleavage of a target can also occur with an antisense strand that doesnot demonstrate high stringency for hybridization in vitro.

Single-stranded interfering RNA: As cited above, interfering RNAsultimately function as single strands. Single-stranded (ss) interferingRNA has been found to effect mRNA silencing, albeit less efficientlythan double-stranded siRNA. Therefore, embodiments of the presentinvention also provide for administration of a ss interfering RNA thathybridizes under physiological conditions to a portion of SEQ ID NO:1 orSEQ ID NO:2 and has a region of at least near-perfect contiguouscomplementarity of at least 19 nucleotides with the hybridizing portionof SEQ ID NO:1 or SEQ ID NO:2, respectively. The ss interfering RNA hasa length of 19 to 49 nucleotides as for the ds siRNA cited above. The ssinterfering RNA has a 5′ phosphate or is phosphorylated in situ or invivo at the 5′ position. The term “5′ phosphorylated” is used todescribe, for example, polynucleotides or oligonucleotides having aphosphate group attached via ester linkage to the C5 hydroxyl of thesugar (e.g., ribose, deoxyribose, or an analog of same) at the 5′ end ofthe polynucleotide or oligonucleotide.

SS interfering RNAs are synthesized chemically or by in vitrotranscription or expressed endogenously from vectors or expressioncassettes as for ds interfering RNAs. 5′ Phosphate groups may be addedvia a kinase, or a 5′ phosphate may be the result of nuclease cleavageof an RNA. Delivery is as for ds interfering RNAs. In one embodiment, ssinterfering RNAs having protected ends and nuclease resistantmodifications are administered for silencing. SS interfering RNAs may bedried for storage or dissolved in an aqueous solution. The solution maycontain buffers or salts to inhibit annealing or for stabilization.

Hairpin interfering RNA: A hairpin interfering RNA is a single molecule(e.g., a single oligonucleotide chain) that comprises both the sense andantisense strands of an interfering RNA in a stem-loop or hairpinstructure (e.g., a shRNA). For example, shRNAs can be expressed from DNAvectors in which the DNA oligonucleotides encoding a sense interferingRNA strand are linked to the DNA oligonucleotides encoding the reversecomplementary antisense interfering RNA strand by a short spacer. Ifneeded for the chosen expression vector, 3′ terminal T′s and nucleotidesforming restriction sites may be added. The resulting RNA transcriptfolds back onto itself to form a stem-loop structure.

Mode of administration: Interfering RNA may be delivered via aerosol,buccal, dermal, intradermal, inhaling, intramuscular, intranasal,intraocular, intrapulmonary, intravenous, intraperitoneal, nasal,ocular, oral, otic, parenteral, patch, subcutaneous, sublingual,topical, or transdermal administration, for example.

Interfering RNA may be delivered directly to the eye by ocular tissueinjection such as periocular, conjunctival, subtenon, intracameral,intravitreal, intraocular, subretinal, subconjunctival, retrobulbar, orintracanalicular injections; by direct application to the eye using acatheter or other placement device such as a retinal pellet, intraocularinsert, suppository or an implant comprising a porous, non-porous, orgelatinous material; by topical ocular drops or ointments; or by a slowrelease device in the cul-de-sac or implanted adjacent to the sclera(transscleral) or within the eye. Intracameral injection may be throughthe cornea into the anterior chamber to allow the agent to reach thetrabecular meshwork. Intracanalicular injection may be into the venouscollector channels draining Schlemm's canal or into Schlemm's canal.

Subject: A subject in need of treatment for ocular angiogenesis or atrisk for developing ocular angiogenesis is a human or other mammalhaving ocular angiogenesis or at risk of having ocular angiogenesisassociated with undesired or inappropriate expression or activity ofHIF1A as cited herein. Ocular structures associated with such disordersmay include the eye, retina, choroid, lens, cornea, trabecular meshwork,iris, optic nerve, optic nerve head, sclera, anterior or posteriorsegments, or ciliary body, for example. A subject may also be an ocularcell, cell culture, organ or an ex vivo organ or tissue.

Formulations and Dosage: Pharmaceutical formulations compriseinterfering RNAs, or salts thereof, of the invention up to 99% by weightmixed with a physiologically acceptable carrier medium such as water,buffer, saline, glycine, hyaluronic acid, mannitol, and the like.

Interfering RNAs of the present invention are administered as solutions,suspensions, or emulsions. The following are examples of possibleformulations embodied by this invention.

Amount in weight % Interfering RNA up to 99; 0.1-99; 0.1-50; 0.5-10.0Hydroxypropylmethylcellulose 0.5 Sodium chloride 0.8 BenzalkoniumChloride 0.01 EDTA 0.01 NaOH/HCl qs pH 7.4 Purified water (RNase-free)qs 100 mL Amount in weight % Interfering RNA up to 99; 0.1-99; 0.1-50;0.5-10.0 Phosphate Buffered Saline 1.0 Benzalkonium Chloride 0.01Polysorbate 80 0.5 Purified water (RNase-free) q.s. to 100% Amount inweight % Interfering RNA up to 99; 0.1-99; 0.1-50; 0.5-10.0 Monobasicsodium phosphate 0.05 Dibasic sodium phosphate 0.15 (anhydrous) Sodiumchloride 0.75 Disodium EDTA 0.05 Cremophor EL 0.1 Benzalkonium chloride0.01 HCl and/or NaOH pH 7.3-7.4 Purified water (RNase-free) q.s. to 100%Amount in weight % Interfering RNA up to 99; 0.1-99; 0.1-50; 0.5-10.0Phosphate Buffered Saline 1.0 Hydroxypropy1-β-cyclodextrin 4.0 Purifiedwater (RNase-free) q.s. to 100%

Generally, an effective amount of the interfering RNAs of embodiments ofthe invention results in an extracellular concentration at the surfaceof the target cell of from 100 pM to 1 μM, or from 1 nM to 100 nM, orfrom 5 nM to about 50 nM, or to about 25 nM. The dose required toachieve this local concentration will vary depending on a number offactors including the delivery method, the site of delivery, the numberof cell layers between the delivery site and the target cell or tissue,whether delivery is local or systemic, etc. The concentration at thedelivery site may be considerably higher than it is at the surface ofthe target cell or tissue. Topical compositions are delivered to thesurface of the target organ one to four times per day, or on an extendeddelivery schedule such as daily, weekly, bi-weekly, monthly, or longer,according to the routine discretion of a skilled clinician. The pH ofthe formulation is about pH 4-9, or pH 4.5 to pH 7.4.

Therapeutic treatment of patients with interfering RNAs directed againstHIF1A mRNA is expected to be beneficial over small molecule treatmentsby increasing the duration of action, thereby allowing less frequentdosing and greater patient compliance.

An effective amount of a formulation may depend on factors such as theage, race, and sex of the subject, the severity of the ocularangiogenesis, the rate of target gene transcript/protein turnover, theinterfering RNA potency, and the interfering RNA stability, for example.In one embodiment, the interfering RNA is delivered topically to atarget organ and reaches the HIF1A-containing tissue such as the retinaor optic nerve head at a therapeutic dose thereby ameliorating an ocularangiogenesis-associated disease process.

Acceptable carriers: An acceptable carrier refers to those carriers thatcause at most, little to no ocular irritation, provide suitablepreservation if needed, and deliver one or more interfering RNAs of thepresent invention in a homogenous dosage. An acceptable carrier foradministration of interfering RNA of embodiments of the presentinvention include the cationic lipid-based transfection reagentsTransIT®-TKO (Mirus Corporation, Madison, Wis.), LIPOFECTIN®,Lipofectamine, OLIGOFECTAMINE™ (Invitrogen, Carlsbad, Calif.), orDHARMAFECT™ (Dharmacon, Lafayette, Colo.); polycations such aspolyethyleneimine; cationic peptides such as Tat, polyarginine, orPenetratin (Antp peptide); or liposomes. Liposomes are formed fromstandard vesicle-forming lipids and a sterol, such as cholesterol, andmay include a targeting molecule such as a monoclonal antibody havingbinding affinity for endothelial cell surface antigens, for example.Further, the liposomes may be PEGylated liposomes.

The interfering RNAs may be delivered in solution, in suspension, or inbioerodible or non-bioerodible delivery devices. The interfering RNAscan be delivered alone or as components of defined, covalent conjugates.The interfering RNAs can also be complexed with cationic lipids,cationic peptides, or cationic polymers; complexed with proteins, fusionproteins, or protein domains with nucleic acid binding properties (e.g.,protamine); or encapsulated in nanoparticles or liposomes. Tissue- orcell-specific delivery can be accomplished by the inclusion of anappropriate targeting moiety such as an antibody or antibody fragment.

For ophthalmic delivery, an interfering RNA may be combined withophthalmologically acceptable preservatives, co-solvents, surfactants,viscosity enhancers, penetration enhancers, buffers, sodium chloride, orwater to form an aqueous, sterile ophthalmic suspension or solution.Solution formulations may be prepared by dissolving the interfering RNAin a physiologically acceptable isotonic aqueous buffer. Further, thesolution may include an acceptable surfactant to assist in dissolvingthe inhibitor. Viscosity building agents, such as hydroxymethylcellulose, hydroxyethyl cellulose, methylcellulose,polyvinylpyrrolidone, or the like may be added to the compositions ofthe present invention to improve the retention of the compound.

In order to prepare a sterile ophthalmic ointment formulation, theinterfering RNA is combined with a preservative in an appropriatevehicle, such as mineral oil, liquid lanolin, or white petrolatum.Sterile ophthalmic gel formulations may be prepared by suspending theinterfering RNA in a hydrophilic base prepared from the combination of,for example, CARBOPOL®-940 (BF Goodrich, Charlotte, N.C.), or the like,according to methods known in the art. VISCOAT® (Alcon Laboratories,Inc., Fort Worth, Tex.) may be used for intraocular injection, forexample. Other compositions of the present invention may containpenetration enhancing agents such as cremephor and TWEEN® 80(polyoxyethylene sorbitan monolaureate, Sigma Aldrich, St. Louis, Mo.),in the event the interfering RNA is less penetrating in the eye.

Kits: Embodiments of the present invention provide a kit that includesreagents for attenuating the expression of an mRNA as cited herein in acell. The kit contains an siRNA or an shRNA expression vector. ForsiRNAs and non-viral shRNA expression vectors the kit also contains atransfection reagent or other suitable delivery vehicle. For viral shRNAexpression vectors, the kit may contain the viral vector and/or thenecessary components for viral vector production (e.g., a packaging cellline as well as a vector comprising the viral vector template andadditional helper vectors for packaging). The kit may also containpositive and negative control siRNAs or shRNA expression vectors (e.g.,a non-targeting control siRNA or an siRNA that targets an unrelatedmRNA). The kit also may contain reagents for assessing knockdown of theintended target gene (e.g., primers and probes for quantitative PCR todetect the target mRNA and/or antibodies against the correspondingprotein for western blots). Alternatively, the kit may comprise an siRNAsequence or an shRNA sequence and the instructions and materialsnecessary to generate the siRNA by in vitro transcription or toconstruct an shRNA expression vector.

A pharmaceutical combination in kit form is further provided thatincludes, in packaged combination, a carrier means adapted to receive acontainer means in close confinement therewith and a first containermeans including an interfering RNA composition and an acceptablecarrier. Such kits can further include, if desired, one or more ofvarious conventional pharmaceutical kit components, such as, forexample, containers with one or more pharmaceutically acceptablecarriers, additional containers, etc., as will be readily apparent tothose skilled in the art. Printed instructions, either as inserts or aslabels, indicating quantities of the components to be administered,guidelines for administration, and/or guidelines for mixing thecomponents, can also be included in the kit.

The ability of interfering RNA to knock-down the levels of endogenoustarget gene expression in, for example, a human ocular cell line isevaluated in vitro as follows. Transformed human cells are plated 24 hprior to transfection in standard growth medium (e.g., DMEM supplementedwith 10% fetal bovine serum). Transfection is performed using Dharmafect1 (Dharmacon, Lafayette, Colo.) according to the manufacturer'sinstructions at interfering RNA concentrations ranging from 0.1 nM-100nM. Non-targeting control siRNA and lamin A/C siRNA (Dharmacon) are usedas controls. Target mRNA levels are assessed by qPCR 24 hpost-transfection using, for example, TAQMAN® forward and reverseprimers and a probe set that encompasses the target site (AppliedBiosystems, Foster City, Calif.). Target protein levels may be assessedapproximately 72 h post-transfection (actual time dependent on proteinturnover rate) by western blot, for example. Standard techniques for RNAand/or protein isolation from cultured cells are well-known to thoseskilled in the art. To reduce the chance of non-specific, off-targeteffects, the lowest possible concentration of interfering RNA should beused that will produce the desired level of knock-down in target geneexpression.

The ability of interfering RNAs of the present invention to knock-downlevels of HIF1A protein expression is further exemplified in Example 1as follows.

EXAMPLE 1 Interfering RNA for Specifically Silencing HIF1A

The present study examines the ability of HIF1A-interfering RNA to knockdown the levels of endogenous HIF-1α protein expression in cultured HeLacells.

Transfection of HeLa cells was accomplished using standard in vitroconcentrations (0.1-10 nM) of HIF1A siRNAs, siCONTROL RISC-free siRNA#1, or siCONTROL Non-targeting siRNA #2 (NTC2) and DHARMAFECT® #1transfection reagent (Dharmacon, Lafayette, Colo.). All siRNAs weredissolved in 1× siRNA buffer, an aqueous solution of 20 mM KCl, 6 mMHEPES (pH 7.5), 0.2 mM MgCl₂. Control samples included a buffer controlin which the volume of siRNA was replaced with an equal volume of 1×siRNA buffer (-siRNA). Forty-eight hours after transfection, the cellswere treated with 100 μM CoCl₂ for 4 h to induce HIF-1α proteinexpression, and western blots were performed to assess HIF-1α level. TheHIF1A siRNAs are double-stranded interfering RNAs having specificity forthe following targets: siHIF1A #1 targets SEQ ID NO:48; siHIF1A #3targets SEQ ID NO:49; siHIF1A #5 targets SEQ ID NO:50; siHIF1A #6targets SEQ ID NO:51. As shown by the data of the FIGURE, each of thefour HIF1A siRNAs reduced HIF-1α protein expression significantly at 10nM relative to the control siRNAs. However, siHIF1A #3 and siHIF1A #6also silenced HIF-1α protein expression significantly at 0.1 nM,indicating that these HIF1A siRNAs are particularly effective relativeto siHIF1A #1 and siHIF1A #5.

The references cited herein, to the extent that they provide exemplaryprocedural or other details supplementary to those set forth herein, arespecifically incorporated by reference.

Those of skill in the art, in light of the present disclosure, willappreciate that obvious modifications of the embodiments disclosedherein can be made without departing from the spirit and scope of theinvention. All of the embodiments disclosed herein can be made andexecuted without undue experimentation in light of the presentdisclosure. The full scope of the invention is set out in the disclosureand equivalent embodiments thereof. The specification should not beconstrued to unduly narrow the full scope of protection to which thepresent invention is entitled.

As used herein and unless otherwise indicated, the terms “a” and “an”are taken to mean “one”, “at least one” or “one or more”.

What is claimed is:
 1. A composition for attenuating expression of ahypoxia-inducible factor-1α (HIF1A) gene, the composition comprising aninterfering RNA having a length of 19 to 49 nucleotides, wherein theinterfering RNA comprises a region of at least 13 contiguous nucleotideshaving at least 90% sequence identity with UAUGUGGAAGUGGCAACUG (SEQ IDNO: 53).
 2. The composition of claim 1, wherein the interfering RNA issingle-stranded, a shRNA, a double-stranded siRNA, or a miRNA.
 3. Thecomposition of claim 2, wherein at least one of the nucleotides of theinterfering RNA is modified on its base portion, sugar portion, orphosphate portion.
 4. The composition of claim 3, wherein at least oneof the nucleotides of the interfering RNA has a 2′-O-methylmodification.
 5. The composition of claim 3, wherein the interfering RNAcomprises a region of at least 15, 16, 17, 18, or 19 contiguousnucleotides of UAUGUGGAAGUGGCAACUG (SEQ ID NO: 53).
 6. The compositionof claim 3, wherein the interfering RNA is a double-stranded siRNAcomprising a first strand and a second strand, and wherein each strandof the double-stranded siRNA has a length of 19 to 49 nucleotides. 7.The composition of claim 6, wherein the first strand of the interferingRNA comprises a region of at least 13 contiguous nucleotides having atleast 90% sequence identity with UAUGUGGAAGUGGCAACUG (SEQ ID NO: 53),and the second strand of the interfering RNA comprises a region of atleast 13 contiguous nucleotides having at least 90% sequence identitywith CAGUUGCCACUUCCACAUA (SEQ ID NO: 52).
 8. The composition of claim 7,wherein at least one of the nucleotides of the first stand and at leastone of the nucleotides of the second strand of the interfering RNA ismodified on its base portion, sugar portion, or phosphate portion. 9.The composition of claim 1, wherein the composition further comprises asecond interfering RNA having a length of 19 to 49 nucleotides andcomprising a region of at least 13 contiguous nucleotides having atleast 90% complementarity to, or at least 90% sequence identity with,the penultimate 13 nucleotides of the 3′ end of an mRNA corresponding toany one of SEQ ID NO: 3, and SEQ ID NO:9-SEQ ID NO:51.
 10. A method ofattenuating expression of HIF1A mRNA in a subject, the method comprisingadministering to the subject an effective amount of the composition ofclaim 1, wherein the expression of HIF1A mRNA is thereby attenuated. 11.The method of claim 10, wherein the interfering RNA is single-stranded,a shRNA, a double-stranded siRNA, or a miRNA.
 12. The method of claim11, wherein at least one of the nucleotides of the interfering RNA ismodified on its base portion, sugar portion, or phosphate portion. 13.The method of claim 12, wherein at least one of the nucleotides of theinterfering RNA has a 2′-O-methyl modification.
 14. The method of claim12, wherein the interfering RNA comprises a region of at least 15, 16,17, 18, or 19 contiguous nucleotides of UAUGUGGAAGUGGCAACUG (SEQ ID NO:53).
 15. The method of claim 12, wherein the interfering RNA is adouble-stranded siRNA comprising a first strand and a second strand, andwherein each strand of the double-stranded siRNA has a length of 19 to49 nucleotides.
 16. The method of claim 15, wherein the first strand ofthe interfering RNA comprises a region of at least 13 contiguousnucleotides having at least 90% sequence identity withUAUGUGGAAGUGGCAACUG (SEQ ID NO: 53), and the second strand of theinterfering RNA comprises a region of at least 13 contiguous nucleotideshaving at least 90% sequence identity with CAGUUGCCACUUCCACAUA (SEQ IDNO: 52).
 17. The method of claim 10, the method further comprisingadministering to the subject an effective amount of a second interferingRNA having a length of 19 to 49 nucleotides and comprising a region ofat least 13 contiguous nucleotides having at least 90% complementarityto, or at least 90% sequence identity with, the penultimate 13nucleotides of the 3′ end of an mRNA corresponding to any one of SEQ IDNO: 3, and SEQ ID NO:9-SEQ ID NO:51.
 18. The method of claim 10, whereinthe composition is administered via a topical, intravitreal,transcleral, periocular, conjunctival, subtenon, intracameral,subretinal, subconjunctival, retrobulbar, or intracanalicular route. 19.The method of claim 16, wherein the composition is administered via atopical, intravitreal, transcleral, periocular, conjunctival, subtenon,intracameral, subretinal, subconjunctival, retrobulbar, orintracanalicular route.